sfgf::Collider Class Reference

Handles collisions. More...

#include <Collider.hpp>

Public Member Functions
void	applyTransform (const sf::Transform &t)
	Applies transform. More...
void	pushBack (sf::Vector2f pt)
	Adds point to internal array. More...
void	clear ()
	Clears points. More...
sf::FloatRect	getGlobalBounds () const
	Returns global bounds. More...
bool	intersects (const Collider &poly) const
	Check for intersection. More...
bool	contains (sf::Vector2f point) const
	Check if point is inside of collider. More...
bool	collides (const Collider &poly) const
	Check if two colliders collide. More...

Static Public Member Functions
static Collider	circle (float radius, size_t cnt=128)
	Returns collider in shape of circle. More...
static Collider	rectangle (sf::Vector2f size)
	Returns collider in shape of rectangle. More...
static bool	lineIntersection (sf::Vector2f p1, sf::Vector2f q1, sf::Vector2f p2, sf::Vector2f q2)
	Check two lines for intersection. More...

Detailed Description

Handles collisions.

Contains basic set of points which can be later transformed to represent bounds of an object. Also supports globalBounds to make collision detection more efficient.
Sample code:

auto circle = sfgf::Collider::circle(5); // Make circle, r = 5
auto rect = sfgf::Collider::rectangle({10, 10}); // Make rectangle (10, 10)

auto t = sf::Transform().translate({9, 0}); // Make transform translating by 9 to the right
circle.applyTransform(t); // Apply that transform to circle

std::cout << std::boolalpha << circle.collides(rect) << std::endl; //True
circle.applyTransform(t); // Apply transform again
std::cout << std::boolalpha << circle.collides(rect) << std::endl; //False

Member Function Documentation

void sfgf::Collider::applyTransform

(

const sf::Transform &

t

)

Applies transform.

Parameters

[in]

t

– transform to use

Used to adjust position/rotation/scale of collider to actual object.
Sample code:

this->collider.applyTransform(this->polygon.getTransform());

Collider sfgf::Collider::circle ( float  radius, size_t  cnt = 128  )

static

Returns collider in shape of circle.

Parameters

[in]	radius	– radius of circle
[in]	cnt	– count of points to make

Returns

new collider

somePolygon.setSampleCollider(sfgf::Collider::circle(7));

void sfgf::Collider::clear

(

)

Clears points.

Simply clears internal array (std::vector), empty collider never detects any collision.

bool sfgf::Collider::collides

(

const Collider &

poly

)

const

Check if two colliders collide.

Parameters

[in]

poly

– collider to check against

Tests whether colliders collide or not. They do, if any of theirs side intersect or if no point of one collider is outside of another.

Returns

True if they collide, False otherwise.

bool sfgf::Collider::contains

(

sf::Vector2f

point

)

const

Check if point is inside of collider.

Parameters

[in]

point

– point to check

Tests if given point is inside of (*this).

Returns

True if point is in collider, false otherwise

sf::FloatRect sfgf::Collider::getGlobalBounds ( ) const

inline

Returns global bounds.

Get the global bounding rectangle of the entity.
The returned rectangle is in global coordinates, which means that it takes in account the transformations (translation, rotation, scale, …) that are applied to the entity. In other words, this function returns the bounds of the collider in the global 2D world's coordinate system.

Returns

Global bounding rectangle of the entity

bool sfgf::Collider::intersects

(

const Collider &

poly

)

const

Check for intersection.

Parameters

[in]

poly

– collider to check

Tests if any side of (*this) intersects with any side of poly.

Returns

True if colliders intersect, False otherwise

bool sfgf::Collider::lineIntersection ( sf::Vector2f  p1, sf::Vector2f  q1, sf::Vector2f  p2, sf::Vector2f  q2  )

static

Check two lines for intersection.

Parameters

[in]	p1	– beginning of line I
[in]	q1	– end of line I
[in]	p2	– beginning of line II
[in]	q2	– end of line II

Returns

True if lines intersect, False otherwise

std::cout << std::boolapha << sfgf::Collider::lineIntersection({0, 0}, {50, 20}, {25, 0}, {25 50}) << std::endl;

void sfgf::Collider::pushBack

(

sf::Vector2f

pt

)

Adds point to internal array.

Parameters

[in]

pt

– coordinates in local system

Can be used to create collider in non–standard shape, aka custom polygon.
Sample code:

while(inputFile >> x >> y) {
    collider.pushBack({x, y});
}

Collider sfgf::Collider::rectangle ( sf::Vector2f  size )

static

Returns collider in shape of rectangle.

Parameters

[in]

size

– dimensions of rectangle

Returns

new collider

somePolygon.setSampleCollider(sfgf::Collider::rectangle({20, 10}));

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The documentation for this class was generated from the following file:

• SFGF/Collider.hpp